Serum, urine, and tissues are commonly analyzed by atomic absorption spectrometry for traces of metals such as calcium, lead, cadmium, magnesium, copper, zinc and iron. The major limitation of this technique is the efficient production of the atomic species in the flame. Modifications involving nebulizers, burners, fuel and support gases, instrumentation and aspirating solvents have led to some increases in sensitivity, but these have been slight when compared to the potential sensitivity enhancement afforded by non-flame atomization techniques. The latter may yield detection limits some three to five orders of magnitude less than by flame sampling with less pretreatment than the flame technique usually requires (especially when complex matrices such as tissues are involved). The long-term goal of the proposed research is to explore the potential of this ultra-sensitive method of analysis for trace metals in biologically and biochemically important substances. This investigator proposes to use atomic spectrometry coupled with a non-flame sampling system which affords greater sensitivity of (10 to the minus 12th power grams absolute), is commercially available, and reduces the amount of pretreatment sufficiently to enable direct analysis of serum, urine, body fluids, and tissue with sample sizes ranging from only 1 to 50 microliters. We will carefully examine the potential of the non-flame technique as applied to real and presently difficult or impossible analytical problems. Samples of biological or biochemical importance will be for principal interest. We also propose to examine the potential of the non-flame technique with renal samples as applied to atomic fluorescence experiments. The orientation will be toward biological samples.